Fiber reinforced cementitious compositions containing hydraulic cement, inorganic mineral fillers and pozzolans as well as chemical additives such as plasticizers and water dispersants have been used in the construction industry to form the interior and exterior walls of residential and/or commercial structures. However, a drawback of such conventional panels is that they do not have sufficient compressive strength to provide a high degree of resistance to ballistic and blast loads.
Current practice for producing ultra-high strength cementitious compositions relies upon efficient particle packing and extremely low water dosage for achieving ultra-high material strength. As a consequence of the raw materials utilized to achieve dense particle packing and the extremely low water usage in these compositions, the cementitious mixtures have extremely stiff rheological behavior with dough like consistency in the freshly mixed state. The stiff consistency makes these mixtures highly unworkable and extremely difficult to process in conventional manufacturing processes for making thin cement-based products and composites.
U.S. Pat. No. 4,158,082 A to Belousofsky discloses a laminated cement based structure with a fiber glass skin that is impact resistant and may use Portland based cements.
U.S. Pat. No. 4,793,892 to Miller discloses an apparatus manufacturing a concrete panel with cement core and fiber glass facing utilizing Portland cement.
U.S. Pat. No. 4,948,429 A to Arfaei discloses a cementitious composition containing portland cement, sand, fumed silica and a polyether.
U.S. Pat. No. 5,724,783 to Mandish discloses a building panel and assembly system composed of Portland cement panel layers attached to a panel framework with multiple layers.
U.S. Pat. No. 6,119,422 B1 to Clear discloses an impact resistant strong structural cementitious building panel with outer facing of fiberglass reinforcing mesh where the composite cementitious has an aggregate core with inner and outer faces of fiberglass mesh.
U.S. Pat. No. 6,176,920 to Murphy disclose a method of method for constructing a cementitious panel of multiple layers utilizing a smoothing head, shearer and screeding process.
U.S. Pat. No. 6,309,457 B1 Guerinet et al. discloses a self-leveling cementitious composition that includes Portland cement, silica sand of maximum 10 mm size or 0-5 mm size, or a blend of 0-0.4 mm and 0-5 mm size; fine mineral aggregates such as fly ash or silica flour having dimensions of less than 200 microns, preferably less than 100 microns; a first plasticizer which is a water-soluble or water-dispersible organic compound containing at least one aminodi(alkenephosphonic) group; and a second water-soluble or water-dispersible plasticizer which is of the polycarboxylic acid type and contains polyether chains. Example 1 indicates a compressive strength in 28 days of 32 MPa (about 4600 psi).
U.S. Pat. No. 6,437,027 B1 to Isomura et al. discloses a cementitious composition containing portland cement, silica sand of less than 5 mm size; and polycarboxylate of 0.01-2.5 wt. %.
U.S. Pat. No. 6,849,118 B2 to Kerkar et al. discloses a cementitious composition containing Portland cement, silica sand of 0 to 6 mm size; and polycarboxylate (ADVA plasticizer).
U.S. Pat. No. 6,858,074 B2 to Anderson et al. discloses a cementitious composition containing portland cement, silica sand, fumed silica, accelerator, retarder, and polycarboxylate high range water reducing dispersant.
U.S. Pat. No. 6,875,801 B2 to Shendy et al. discloses a cementitious composition containing portland cement, sands, fumed silica and polycarboxylate of 0-2 wt %.
U.S. Pat. No. 6,942,727 B2 Daczko et al. discloses a high early strength cementitious member that includes Portland cement; fine aggregate such as silica sand, the fine aggregate are materials that almost entirely pass through a Number 4 sieve, coarse aggregate such as sand, the coarse aggregate are materials predominantly retained on a Number 4 sieve; silica fume pozzolan; 0.025-0.7% polycarboxylate dispersant based on dry weight of cement; and structural synthetic fibers. The cementitious member can be used to make wall panels. The cementitious member can exhibit 24 hour compression strength greater than 10,000 psi; however these compositions do not contain a pozzolan.
US Pat. App. Pub. No. 2002/0004559 to Hirata et al. discloses a cementitious composition containing portland cement, sands, fumed silica and polyethers of more than 0.5% wt. e.g. 2 wt. %.
US Pat. App. Pub. No. 2004/0149174 to Farrington et al. discloses a cementitious composition containing portland cement, sands, fumed silica and polycarboxylate of 0.01-0.2 wt %.
US Pat. App. Pub. No. 2004/0198873 to Bury et al. discloses a cementitious composition containing portland cement, silica sand, fumed silica and polycarboxylate of 0.02-2 wt %.
US Pat. App. Pub. No. 2004/0211342 to Sprouts et al. discloses a cementitious composition containing portland cement, silica sand, fumed silica and polycarboxylate of 0.1-2 wt %.
US Pat. App. Pub. No. 2004/0231567 to Dulzer et al. discloses a cementitious composition containing portland cement, sand, fumed silica and polycarboxylate of 0.1-10 wt % of the total dry cementitious binder.
US Pat. App. Pub. No. 2005/0139308 to Aldea disclose a system and method using a FRP reinforced cementitious material or composite that may include Portland cement, fly ash, silica fume, resins, sand, glass fibers, resins, water, accelerators, fillers, setting retardants, dispersing agents; involves multiple layers and toweling to smooth between layers; and may be used to strengthen structures against earthquakes and explosions. In Aldea, the layers are applied in situ by toweling and are not applied to form a free standing panel which can be attached to a frame. The structure made in Aldea has two concrete layers bonded to a fiberglass mat.
US Pat. App. Pub. No. 2005/0239924 to Lettkeman et al. discloses a cementitious composition containing portland cement, fine sands, fumed silica and polycarboxylate of 0.05-2.5 wt %.
US Pat. App. Pub. No. 2005/0274294 to Brower et al. discloses a cementitious composition containing portland cement, fine sands, fumed silica and polycarboxylate of 1-4% wt.
US Pat. App. Pub. No. 2006/0281836 to Kerns et al. discloses a cementitious composition containing portland cement, fine sands, fumed silica and polycarboxylate.
US Pat. App. Pub. No. 2007/0125273 to Pinto discloses a cementitious composition containing portland cement, fine sands, fumed silica and polycarboxylate such as 1-2 wt. %.
US Pat. App. Pub. No. 2007/0175126 to Tonyan et al, incorporated herein by reference in its entirety, discloses a structural cementitious panel.
US Pat. App. Pub. No. 2007/0228612 A to Durst et al., incorporated herein by reference, discloses blast resistant concrete also suitable for limiting penetration of ballistic fragments.